Precision equipment used in aviation and other critical industries need to be tested before they are placed in use Typically, a manufacture of such precision equipment is required to verify that the equipment will work within specific tolerances required by the purchaser. To assess the tolerance of such equipment, the equipment is subjected to test simulation equipment. An example of precision equipment includes an inertial measurement unit (IMU) that is used in guidance systems of ground-to-air missiles. IMUs require verification of performance when subjected to in-flight vibrations. To provide the verification, test equipment such as a shaker table is used to generate random vibrations that simulate the environment the IMU will experience in service. The performance of the IMU (or device under test) is then determined.
A shaker table is designed to move linearly along one axis. However, a problem encountered in testing precision equipment with a shaker table is that shaker table itself introduces an unknown amount of angular displacement error (noise) due to mechanical nature of the shaker table. This angular displacement error causes the true performance of the precision equipment to not be accurately accessed. The ability to measure the angular displacement caused by the shaker table is difficult because it is typically very small such that conventional means are ineffective.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a method of determining the angular frequency displacement caused by test equipment so it can be factored out of test results of devices tested by the equipment.